Centrifuge



Feb. 8, 1938.4

J. sCHAAF CENTRIFUGE Filed Janfsov, 1 955 2 Sheets-Sheetl f E m R6, me; mn Vh ma v. B

2 Sheets-Sheet 2 J. SCHAAF CENTRIFUGE Filed Jan. 30, 1935 Feb. 8,'

20 INVENTOR FIGA Patented Feb. 8, 1938 PATENT OFFICE CENTRIFUGE John Schaaf,

Buffalo, N. Y.

Application January 30, 1935, Serial No. 4,107

11 Claims.

My invention relates to means for quickly separating the excess moisture from sewage sludge or screenings and more particularly to centrifugal means for so doing.

Sewage solids or sludge from a-sewage treatment plant where said solids or sludge is collected in a settling tank, or the solids collected from aVA screen, contain a large percentage of water. Where said solids or sludge is to be dis- .posed of by Adehydrating sufficiently for use as a fertilizer or in an incinerator, it requires considerable fuel to get rid of the excess moisture.

One method of preliminary drying is to spread the-sludge or solids over drying beds and allowing it to dry out, which takes considerable time and a larger area than is always conveniently available in congested districts. Y The principal object of my invention is to provide means forl centrifugally separating considerable of the moisture from sewage solids or sludge.`

Another object is to provide means for separatingy a percentage of the moisture from sewage solids or sludge by making as nearly as possible acontinuous operation from collecting the solids or sludge to its disposal.

v .With the foregoing and other objects in view which will appear yas the description proceeds, the invention consists in certain features of novelty in the construction, combination and arrangement of parts by which the said objects are attained, the invention being more particularly construction and arrangement of parts without departing fromA the spirit or sacrificing any of `theadvantages of the invention as set forth in the appended claims'.

Referring to the drawings: y

Fig. 1 isa vertical sectional elevation of a. centrifuge and sectioned on the lines 'I--l and 1-1 of Fig. 4, showing buckets adapted to be rotated by the motion of the centrifuge, with means for feeding a ltering medium into said buckets and means for feeding sewage matter into said buckets and continuously discharging the separated liquids and intermittently discharging the solids from said sewage matter.

Fig.l2 is a side elevation of a collar and cam shown in section in Fig. 1. f

Fig. 3 is a sectional elevation on line 9-9-9-9 of Fig 4 (with thebucket removed) showing the mechanism for opening and rclosing a valve to control the feeding of filtering medium to the sewage separating bucket.

Fig. 4 is a plan of a portion of the modification of Fig. l and partially sectioned at places marked I0, I0 and I0 which are on the lines Ill-I0, 5 I0-I0'-I0', and I0-I0" of Fig. 1. l

For a continuous operation of dehydrating sewage a. centrifuge is provided as shown in Figs. 1 to 4 and with means for supplying a filtering medium to assist in ltering the sewage as well as to prevent clogging of the screen. The filtering medium employed can be of any suitable granulated material as sand, crushed stone or other material to be disposed of with the sewage 'solids or to be recovered and used again. The filtering material can also be a granulated coal or the like to furnish combustible material when it is desired to burn the sewage solids.

In Figs. l to 4, Ia is the shaft to which the body 2a is fastened for rotation. 3 is the shaft lower bearing mounted in pedestal 5 and having flange 4 for supporting body 2a while 6 is the shaft upper bearing. 1 is a hollow truncated cone forming a chamber 8 and mounted on top of the body 2a. Pipe II projects into the open- 2 ing III for introducing the sewage matter into chamber 8 and having a control valve I2. The hollow truncated cone 1 is surrounded by another hollow truncated cone 44 leaving an annular space between said cones to provide a cham- 30 ber 45 to hold a filtering medium to be introduced by means of a spout 46.

The channel I8 in the form of a ring is fastened to body 2a by means of a support I5a which contacts alternately with the periphery of 35 said body 2ar and the inside of channel I8. Between the top of channel I8 and the cone 44 are braces I9a. Fastened to and spaced around the periphery of the channel I8 are brackets 20, 20 etc., with two bearings 2l to each bracket. Also fastened to the periphery of channel I8 `and spaced between each two brackets 20 is a housing 4lk shaped in the form of a ring as viewed from the side in Fig. 1 but with a portion cut away opposite the channel I8. Bucket 48 fits in and rotates in housing 41 by means of shaft 49 which rotates in bearings 2l. The bucket 48 is shaped like a spool with end walls and a hub and partitioned lengthwise of the hub to divide it into quarters to form four chambers 50 each of which is open on the periphery of said bucket and spanned near the center by a screen '5I to form a space 52 having holes 53 in the end walls through which liquid can be discharged.

54 is a tube having a passage 55 communicating with thev passage 56 in housing 41 and the annular chamber in kcone 44 for conveying filtering medium from chamber 45 into chamber 50. The passage 33 in body 2a opens at its upper end into the chamber 8 and at its lower end into the tube |1a through the support |5a to communicate with the chambers 58 of the rotating bucket 48 in housing 41. As a means for rotating the buckets 4B a roller 51 is supported near the upper -bearing 6. A collar 58 adapted to slide vertically on the outside of shaft la and bear against the roller 51 is pinned through vertical slots by means of pin 59. 68 is a cam on collar 58 for contacting with roller 51 at each rotation of shaft la and collar 58.

The cam 68 is shown demountably attached to collar 58 by means of agroovetoallowfor substituting cams of different size and two or more of such grooves are provided to allow for :using morethan one'cam'as desired. The lower end of shaft Ia is hollow and holds a long upper rod'l and a short lower rod 62 between Awhich vrestsgtheendof the horizontal arm of bell-crank L63.

,roller l'bymeans of the spring '64 acting through The collar 58 is held in contact with the the short rod 62, end of the horizontal arm of bell "cranktt, long`rod '6| and pin-59. 65 is a plug to close the end of shaft la and support the spring 464.

The horizontal arm-of bellV crank'63 extends jthrough a slot 66 in shaft la and is pivoted at 61 in the body 2a. The toothed wheel 68 is fastened on shaft49 for rotating bucket 48 and is operated by the ratchet pin 69 which is connected to 'the vertical arm of the'bell crank 63 by means of rthepivoted rods 10, 1| and 12' supportedin bearings 13 and 14. `15 isa' spring'for holding ratchet pin 69 in operative contact with the teeth of the 'whee1'68. The bucket 48ts in the housing 41 `withsuflicieni', friction to 'hold it stationary except as rotated by the wheel A68'and as the housing 41and Vbucket kg48wea1 additional friction is.

supplied by means of a spring 16 bearing against end of bucket `48 (section of bucket `48 in Fig- |1'is provided in the tube-54; Referring `to Figs. 1 tof 4; the valve-11 is flat and in the form of an 4arcA ofa circle to slide through the housing 18 and pivoted at 19, 19 by means of arms 80, 480 83 is a port through valve 11 to register with the passage ofthe tube 54 to open rsaid valve 11. 84,84 are weights connected to hubs V"8|, 82 to keep the valve `11 closed at all times except when 'opened by the cams` 185 (one of which is provided for each chamber 58) on wheel86 which is fastened on bucket shaft 49. `81 is a roller Von arm 88 attached to shaft 89, and which-is also attached to hub 82, for'opening valve 11 when roller-81 Vis raised by one ofthe cams YY85. The shaft Sil-operates through bearings'QlL'Q (Fig. 4).

In' Fig. l the valve 11' is. shown closing the passage --55 and in Fig. -Sthe valve `I'|'1 is lshownin position for opening the passage 55 in tube54.

aimbot In the sectional View of the bucket 48 'in 1 a medium 9| (as fine coal) is shown covering the screen 5|. The medium 9| can be used dry but is preferably carried in water forY free flowing and is introduced in the correct quantity by proper timing of the duration of the opening of valve 11. The use of water in carrying the medium is also of advantage in that the water draining through the screen 5| leaves the medium in proper position on the screen where desired for collectingthe solids from the sewage.

The operation of the centrifuge and the rotating buckets 48 is as follows:

The centrifuge is rotated by its shaft |a,

medium fed into chamber 45 and sewage into chamber 8.

press frod 6 I ,'endof horizontal arm of bell Vcrank ``|53 and 1od162 against the spring-84, -andin so doing operate the toothed `wheel V68 and the bucket 48 by means o-f the' ratchet pin 89 and rods 18, v:1| and 12 connected to bell -crank 63. As soon-as the-cam v6|! passes roller-'51 the return 'movement ofthe operating parts justenumerated will be accomplished by the spring'64.

In vrotating bucket 48 Aa chamber 5|) is first brought into position toreceivev thefltering medium-from chamber 45 whenthe valve 11 is opened 4by the cam 85 and wheel 86 and then closed by the weights 84 actuated Aby centrifugal force. Weights 84 are located to keep valve 11 closed by gravity acting on said weights when the centrifuge is at rest. VThe water carrying-the filtering mediumis drained through the screen '5| leaving the-medium 9| covering-said screen 5|. Y On further rotation'- of bucket-48chamber 50 4is brought into positiontoreceivethe sewage matter from chamber 8 through passage y33 and Ytube |1a. The 4sewage `vliquid `is discharged through the filtering medium 9|, the 4screen 5|, space '52fand holes 53. After the-chamber-5 'passes theA positionA to receive sewage from chaml ber 8 the balance of moisture in the sewage-is discharged from said chamber *50 -by the centrifugal force created by the rotating centrifuge and Vupon rotation of the bucket `-48 vto -ibring chamber 50 to the out away -outer portion of housing l11H-the sewage solids collected rtogether withtheltering medium vare-discharged by being thrown out by the centrifugal action of the rotating centrifuge. Y

YAsfthe centrifuge rotates several hundred times a minutethe toothed'wheel is proportioned to rotate-buckets`48 to-dischargesewage solids from chambers-58 as often as desired.Y Having thus Vdescribed my invention,1 claim:

1. A centrifuge includingV a body, means to rotate said body, a chambercn said body,'means to introduce sewage-matter into said body chamber, f

aromoe ,.trdischafge the liquid from, said bucket-and ,i ineanfsfto discharge the solids from. said bucket Vfchambefr.`l

filtering medium chamber, a Abucket suppc'irt'edl opposite the periphery of said body, a chamber y 'insaidbuckeh connecting passage means from said body sewage chamber to said bucket chamber, connecting passage means from said body filtering medium chamber to said bucket cham- Y, ber, means to rotate said bucket to bring said bucket chamber into and out of communication .with said body filtering medium chamber and said body sewage chamber, a screen in said bucket chamber, andmeans to rotate said body and centrifugally discharge vrst the liquid from the sewage matter and second the filtering medium and sewage solids.

3. A centrifuge including a body, a chamber for sewage matter on lsaid body, a chamber for filtering medium on said body, means to'introduce sewage matter into said sewage chamber, means tro/introduce filtering medium into said filtering medium chamber, a bucket supported opposite the periphery of said body, a chamber in said bucket, connecting passage means between said vrbody `sewage chamber and said bucket chamber,

Y connecting passage means vbetween said body filtering chamber and said bucket chamber,

meansto rotate'said bucketto bring said bucket chamber first into communication with said body filtering medium chamber to receive filtering medium and second into communication with said body sewage Ychamber to receive sewage matter, a screen in said bucket chamber, means to rotate said body and centrifugally discharge and sewage solids and means to control the feed'- ing of filtering medium fromsaid body filtering Amedium chamber to said bucket chamber.

4; A centrifuge including a body, a chamber for sewage matter on said body, means to introduce sewage matter into said sewage chamber, a chamber for filtering medium on said body,

- means tointroduce filtering medium into said medium chamber, a bucket rotatably mounted adjacent said body, a chamber in said bucket,y

"y va screen in said bucket chamber,.passage means between said body sewage chamber and said bucket chamber, passage means between said body medium chamber and said bucket chamber,

Y valve in said medium passage, cam means to ysaid body and centrifugally separate the liquid fromthe solids of the sewage matter by means f of said screen and centrifugally discharge the separated liquid and solids.

. 5. A centrifuge including a, body, a chamber j for a liquid mixture on said body, a chamber for ,i filtering medium on said body, abucket mounted adjacent'said body, a screen in said bucket, passage means between said body sewage chamber Vjand said bucket, passage means between sald body medium chamber and said bucket, means to'rotate said body and means to rotate said f bucket, said bucket rotating means operated by the rotation of said body whereby filtering medium and sewage' matter are fed into said bucket and'whereby therotation of said body separates Vthe liquid from the sewage solids and separately `discharges the'lliquid andy solids from said bucket. 5 6. A centrifuge including `a body, chamber means on said body to separately hold a liquid .mixture and filtering medium, a bucketmounted [adjacent said body chambers in said'bucket, a

screen in each chamber in said bucket, separate passage means for a liquid mixture anda filter- `ing mediurr'infrom.l said body chamber to said bucket, means to rotate said body to separately feed.first filtering medium and second liquid mixture into each chamber of said bucket and centrifugally discharge the liquid through its screen and from said bucket and means to operate said bucket and discharge the filtering medium together with the solids collected by each screen.

7. A centrifuge including a body, a sewage chamber on said body, a chamber for a filtering medium mixture on said body, a bucket mounted adjacent said body, a screen in said bucket, passage means between said sewage chamber. and said bucket, passage means between said medium chamber and said bucket, means to rotate said body, means to operate said bucket from the rotation of said body to first receive filtering medium mixture and then sewage and 'valve means actuated by the operation of said bucket to control the feeding of filtering medium mixture to said bucket, said bucket operated by the rotation of said body.

8. A centrifuge including a body, a liquid mixture chamber on said body, a housing mounted adjacent said body, a bucket rotatably mounted in said housing, means to form multiple chambers in said bucket, a screen in each of said bucket chambers, passage means connecting said body chamber and said bucket, means to form a discharge opening in said housing opposite said passage means, means to rotate said body, means to rotate said bucket from the rotation of said body and bring each of its chambers in succession first into communication with said body chamber to receive mixture from said mixture chamber and then into communication with said housing discharge opening to discharge the solids from said mixture.

9. A centrifuge including a body, a shaft, means to rotate said shaft and body, a chamber for sewage matter on said body, means to 1ntroduce sewage matter into said body chamber, a bucket supported opposite the periphery of said body, partition means longitudinally dividing said bucket into chambers, liquid discharge passage means from each chamber adjacent the center of said bucket to form a continuous liquid discharge, means to screen the liquid discharge passage in each chamber, passage means from said body chamber to said bucket, means to rotate said bucket to bring said bucket chambers alternately into communication with said body chamber passage means to receive sewage matter from said body chamber and means to discharge the resultant sewage solids from one of said bucket chambers during the sewage feeding into another of said bucket chambers.

10. A centrifuge including a body, a chamber for a liquid mixture on said body, buckets mounted adjacent said body, chambers in each bucket formed by partitions extending longitudinally of said bucketand meeting in the center of said bucketto inclose a central angle in each chamber, a screen across the central angle of each chamber, a liquid dscharge'passae from the angle Abottom in each chamber, feedingpassage'means collected onrsaid screens. V Y.

l Y11. In a centrifuge for utilizing a filtering medium, the combinatiomof a body, meansto rotate said body,v a chamber for said ltering medium on said body, meansto introduce said ltering medium into said body chamber, a Vbucket',

`mounted adjacent said body, a Vchamber in said .-bucket, a lscreen in said bucket chamber, connesting passage means from said body chamber to` saidbucket chamber, Valve means in Vsaid vconnecting passage means, meansto openrsaid valve and means to close said valve.

JOHN scHAAF. 

